Our aim in Project II is to explore the neurobiological foundations of speech using tools that allow us to monitor brain activity directly. Two major foci of attention are tests of our motor theory of speech perception. We will find the locus of phonetic processing in the brain. We expect to find a discrete locus, consistent with the motor theory's claim that phonetic processing is achieved by a system that is distinct from the auditory processing system. In addition, we will explore neurobiological properties of the module. A specific goal is to test the claim that the module recruits brain systems that control speech production in the service of speech perceptions. Another goal is to explore the role of lexicality in phonetic processing. We know from behavioral research that the way in which a listener identifies an ambiguous phone can be affected by which possible identity, in combination with the other phones in a sequence, forms a read word of the language. We will ask how the lexicality of an acoustically presented sequence of phonetic segments affects the location and magnitude of brain activation. A final goal is to explore the role of morphological structure in the mental lexicon. Our colleagues have explored this issue in relation to visual word recognition. We focus on auditory word recognition.